A chemical reaction appears to be the cause of a fire at Altec Engineering.

Crews from the Elkhart Fire Department were called to the business in the 2400 block of West Mishawaka Road around 11:45 p.m. on Friday, May 31.

On arrival, crews found heavy smoke throughout the building.

Once inside, they found the fire coming from a trash hopper.

It took quite some time to clear the smoke due to the size of the building.

The fiberglass inside the trash hopper caused the chemical reaction and combustion, starting the contents on fire and burning up the wall to the ceiling, according to fire officials.

The sprinkler system was activated and contained the fire until fire crews arrived.